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1.
In this paper, we consider the positive solution of the Cauchy problem for the following doubly degenerate parabolic equation
ut-div(|?u|p ?um)=uqu_t-{\rm div}(|\nabla u|^{p} \nabla u^m)=u^q  相似文献   

2.
We show that any entropy solution u of a convection diffusion equation ?t u + div F(u)-Df(u) = b{\partial_t u + {\rm div} F(u)-\Delta\phi(u) =b} in Ω × (0, T) belongs to C([0,T),L1loc(W)){C([0,T),L^1_{\rm loc}({\Omega}))} . The proof does not use the uniqueness of the solution.  相似文献   

3.
In this paper we study the discrete nonlinear equation
-Dun+enun-wun=scngn(un)un,-\Delta u_{n}+\varepsilon_{n}u_{n}-\omega u_{n}=\sigma \chi_{n}g_{n}(u_{n})u_{n},  相似文献   

4.
In this paper we study the existence of a solution in ${L^\infty_{\rm loc}(\Omega)}In this paper we study the existence of a solution in Lloc(W){L^\infty_{\rm loc}(\Omega)} to the Euler–Lagrange equation for the variational problem
inf[`(u)] + W1,¥0(W) òW (ID(?u) + g(u)) dx,                   (0.1)\inf_{\bar u + W^{1,\infty}_0(\Omega)} \int\limits_{\Omega} ({\bf I}_D(\nabla u) + g(u)) dx,\quad \quad \quad \quad \quad(0.1)  相似文献   

5.
We study the long-term behaviour of the parabolic evolution equation $\[u'(t)=A(t)u(t)+f(t), t>s,\quad u(s)=x. \]$\[u'(t)=A(t)u(t)+f(t), t>s,\quad u(s)=x. \] If A(t) A(t) converges to a sectorial operator A with s(A)?i \Bbb R = ? \sigma(A)\cap i \Bbb R =\emptyset as t?¥ t\to\infty , then the evolution family solving the homogeneous problem has exponential dichotomy. If also f(t)? f f(t)\to f_\infty , then the solution u converges to the 'stationary solution at infinity', i.e., limt?¥u(t) = -A\sp-1f=:u,        limt?¥u¢(t)=0,        limt?¥A(t)u(t)=Au. \lim_{t\to\infty}u(t)= -A\sp{-1}f_\infty=:u_\infty, \qquad \lim_{t\to\infty}u'(t)=0, \qquad \lim_{t\to\infty}A(t)u(t)=Au_\infty. .  相似文献   

6.
We study profiles of positive solutions for quasilinear elliptic boundary blow-up problems and Dirichlet problems with the same equation:
- eDp u = f(x,u)inW, - \varepsilon \Delta _p u = f(x,u)in\Omega ,  相似文献   

7.
In this paper we study the boundary limit properties of harmonic functions on ℝ+×K, the solutions u(t,x) to the Poisson equation
\frac?2 u?t2 + Du = 0,\frac{\partial^2 u}{\partial t^2} + \Delta u = 0,  相似文献   

8.
This work is concerned with the fast diffusion equation
ut = ?·(um-1 ?u)        (*) u_t = \nabla \cdot \big(u^{m-1} \nabla u\big) \qquad (\star)  相似文献   

9.
We investigate the stochastic parabolic integral equation of convolution type
u=k1*Apu +?k=1 k2*gk+u0,   t 3 0, u=k_1\ast A_pu +\sum\limits_{k=1}^{\infty} k_2\star g^k+u_0, \; t\geq 0,  相似文献   

10.
We consider the Neumann initial boundary-value problem for the equation
ut = \textdiv( um - 1| Du |l- 1Du ) - up {u_t} = {\text{div}}\left( {{u^{m - 1}}{{\left| {Du} \right|}^{\lambda - 1}}Du} \right) - {u^p}  相似文献   

11.
For the damped-driven KdV equation $ \dot{u}-{\nu}u_{xx} + u_{xxx} - 6uu_{x} = \sqrt{\nu}\,\eta(t, x), x \in S^1, \int udx \equiv \int \eta dx \equiv 0, $ with 0 < ν ≤ 1 and smooth in x white in t random force η, we study the limiting long-time behaviour of the KdV integrals of motions (I 1, I 2, . . . ), evaluated along a solution u ν (t, x), as ν → 0. We prove that for ${0 \leq \tau := {\nu}t \lesssim 1}For the damped-driven KdV equation
[(u)\dot]-nuxx + uxxx - 6uux = ?{n} h(t, x), x ? S1, òudx o òhdx o 0, \dot{u}-{\nu}u_{xx} + u_{xxx} - 6uu_{x} = \sqrt{\nu}\,\eta(t, x), x \in S^1, \int udx \equiv \int \eta dx \equiv 0,  相似文献   

12.
We construct an a priori estimate of the seminorm á uxx ña, [`(W)] {\left\langle {{u_{xx}}} \right\rangle_{\alpha, \bar{\Omega }}} for solutions to the problem
Fm[ u ] = f;    u |?W = F {F_m}\left[ u \right] = f;\quad \left. u \right|{_{\partial \Omega }} = \Phi  相似文献   

13.
In this paper, we consider the wave equation
u" - Du = |u|r uu' - \Delta u = |u|^\rho u  相似文献   

14.
Given a bounded open regular set W ì \mathbbR2{\Omega \subset \mathbb{R}^2} and x1, x2, ?, xm ? W{x_1, x_2, \ldots, x_m \in \Omega}, we give a sufficient condition for the problem
-div(a(u)?u) = r2 f(u) -{\rm div}(a(u)\nabla u)= \rho^{2} f(u)  相似文献   

15.
We study the Cauchy problem in \mathbbRN{\mathbb{R}^N} for the parabolic equation
ut+div F(u)=Dj(u),u_t+{\rm div}\,F(u)=\Delta\varphi(u),  相似文献   

16.
We discuss the existence and the asymptotic behavior of positive radial solutions for the following equation:
Dp u(x)+f(u,|x|)=0, \Delta_p u({\bf x})+f(u,|{\bf x}|)=0,  相似文献   

17.
In this paper we consider the following 2D Boussinesq–Navier–Stokes systems
lll?t u + u ·?u + ?p = - n|D|a u + qe2       ?t q+u·?q = - k|D|b q               div u = 0{\begin{array}{lll}\partial_t u + u \cdot \nabla u + \nabla p = - \nu |D|^\alpha u + \theta e_2\\ \quad\quad \partial_t \theta+u\cdot\nabla \theta = - \kappa|D|^\beta \theta \\ \quad\quad\quad\quad\quad{\rm div} u = 0\end{array}}  相似文献   

18.
In this paper we study the quenching problem for the non-local diffusion equation
ut(x,t) = òW J(x - y)u(y,t)dy + ò\mathbbRN\W J(x - y)dy - u(x,t) - lu - p(x,t) {u_t}(x,t) = \int\limits_\Omega {J(x - y)u(y,t)dy + \int\limits_{{\mathbb{R}^N}\backslash \Omega } {J(x - y)dy - u(x,t) - \lambda {u^{ - p}}(x,t)} }  相似文献   

19.
20.
Qingliu Yao 《Acta Appl Math》2010,110(2):871-883
This paper studies the existence of a positive solution to the second-order periodic boundary value problem
u¢¢(t)+l(t)u(t)=f(t,u(t)),    0 < t < 2p,  u(0)=u(2p), u(0)=u(2p),u^{\prime \prime }(t)+\lambda (t)u(t)=f\bigl(t,u(t)\bigr),\quad 0相似文献   

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